1. Field of the Invention
The present invention involves the technical field of packing pasty products, especially involves a dual tube container with one way valves, and a method for making the dual tube container with applicator, which contains two kinds of pro rata pastes in the inner, and outer tubes, by the built-in one way valves being opened or closed, to allow or forbid the two pastes to flow out
2. Description of the Related Art
Currently, plastic tube is widely used to products of cosmetics, medicine, food, dentifrice, medical ointment, excite mostly adopts a single tube structure of squeeze type, which contains pasty cosmetics, etc. in a tube, and while being used, the cap is opened, and the tube is squeezed to make the pasty cosmetics flow out to be used. Some cosmetics, such as a sunscreen lotion, a lipstick, a lip balm, or a hair dye, often require that multiple pastes are pro rata blended to be used, which currently are still separately packed with a single tube, so the product cost is increased. While being used, each single tube is separately opened to separately squeeze two kind of pastes out to be blended before being used, which are not convenient for using and carrying.
A Taiwan patent with the publication number of M297920 disclosed an improved dual tube container structure. The improved dual tube container structure comprises an inner tube, an outer tube, a middle sleeve, and a spigotjoint provided with an outlet and an inlet; the middle sleeve close contacts the spigotjoint to be connected by socket joint; the gear seat below the spigotjoint and the registering section at the lower section of the middle sleeve are together squeezed into the tube orifice of the outer tube, so as to make the spigotjoint and the middle sleeve to be fixed to the tube orifice part of the outer tube. By this design, different cosmetics can be separately filled in the inner tube and the outer tube, and at the same time two kinds of pro rata cosmetics can be squeezed out to be blended to use, so as to provide convenience to the users.
But in this improved structure, the fixing of the inner tube and outer tube needs implement via the parts such as the spigotjoint and the middle sleeve with complicated shapes; the complicated structure make the product cost to increase. Besides, the improved structure has no valve switch; the external liquid out path in the spigotjoint keeps being connected to the outlet of the spigotjoint all along; the outlet of the liquid out path of the inner tube keeps opening all along; the pastes (or the contents) in the inner tube and the outer tube are blended at the outlets in the tubes; the pastes at each outlets easily get bad or dry, leading to the blocking phenomenon. At the same time, when the tube is squeezed to generate a resilience pressure, the blended contents at the outlets in the tubes will be sucked back into the tubes, which causes the contents separately contained in the inner tube and the outer tube to be polluted, so, the contents being separately contained in the inner tube and the outer tube loses its meaning.
Besides, the external liquid out path in the spigotjoint is comparatively long, and each outlet is small, so it can only fits the traditional technology that the contents are separately filled from the tube tail before the tube tail is sealed.